Genetic basis of male fertility.

We are in the age of genetic discovery. Now the human genome has been completely sequenced1, there will be increasing understanding and ability to manipulate biochemical pathways downstream of genes. At the same time, further development of in vitro fertilization (IVF) and intracytoplasmic sperm injection(ICSI) will enable procreation in situations that were formerly impossible and when there may be an increased possibility of genetic abnormality. Furthermore, preimplantation diagnosis will enable defects to be diagnosed and will give the opportunity for the couple to decide whether to continue with treatment towards a pregnancy or not. Thus, there is a need for clinicians to have a good knowledge of the gentics and hereditary aspects of male (and indeed female) infertility and for couples to have access to correct information and expert counselling. Also, there are ethical implications of these scientific and clinical advances for the future child, the individual, the couple and society. There is increasing public unease about this new science of reproduction and, in the UK, there is regulation by law; thus, there is a need for clinicians and scientists to give accurate information in everday language to the public.